Coating compositions comprising a silane modified compound

ABSTRACT

A coating composition comprising an acid functional acrylic resin and a silane modified compound is disclosed. Substrates coated at least in part with such coatings are also disclosed.

FIELD OF THE INVENTION

The present invention is directed to a coating composition comprising anacid functional acrylic resin and a silane modified compound.Substrates, including packages, coated at least in part with such acoating are also within the scope of the present invention.

BACKGROUND OF THE INVENTION

The application of various polymeric coatings to metallic substrates,including metal cans such as food, beverage and cosmetic containers, toretard or inhibit corrosion is well established. Coatings are applied tothe interior of such containers to prevent the contents from contactingthe metal of the container. Contact between the metal and the food,beverage or cosmetic can lead to corrosion of the metal container, whichcan then contaminate the product. This is particularly true when thecontents of the container are acidic in nature, such as tomato-basedproducts and soft drinks.

Certain coatings, particularly in the packaging industry, must undergoextreme stresses in the course of preparation and use of the packagingcontainers. In addition to flexibility, packaging coatings may also needresistance to chemicals, solvents, and pasteurization processes used inthe packaging of beer and other beverages, and may also need towithstand retort conditions commonly employed in food packaging. Inaddition to corrosion protection, coatings for food and beveragecontainers should be non-toxic, and should not adversely affect thetaste of the food or beverage in the can. Resistance to “popping”,“blushing” and/or “blistering” may also be desired.

Bisphenol A (“BPA”) contributes to many of the properties desired inpackaging coating products. The use of BPA and related products such asbisphenol A diglycidyl ether (“BADGE”), however, has recently come underscrutiny in the packaging industry. Substantially BPA-free coatingshaving properties comparable to coatings comprising BPA are thereforedesired. A reduced use of formaldehyde in coatings is also desired.

SUMMARY OF THE INVENTION

The present invention is directed to a coating composition comprising anacid functional acrylic resin and a silane modified compound. Substratescoated at least in part with such coatings are also within the scope ofthe present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a coating composition comprising anacid functional acrylic resin and a silane modified compound.Functionality on the silane modified compound and the carboxylic acidfunctionality on the acrylic resin react during cure to form acrosslinked coating. For example, if the silane modified compoundcomprises an aminosilane modified compound, an amide is formed uponreaction with the carboxylic acid functionality.

The acrylic resin may be formed by using any number of acrylic monomers,including styrene, alkyl (meth)acrylates such as ethyl (meth)acrylate,methyl (meth)acrylate, and butyl (meth)acrylate, functional acrylatessuch as hydroxyethyl (meth)acrylate, and acrylamides such as n-butoxymethyl acrylamide. For example, an acid functional (meth)acrylic acidand an alkyl (meth)acrylate may each be used. Mixtures of (meth)acrylicresins can also be used. The acrylic resin used in the coatingcompositions should have unreacted carboxylic acid functionality.According to the present invention, the acrylic resin may exclude or besubstantially free of styrene, ethyl acrylate, acrylamide and/or vinylchloride monomers as these monomers may not be desired in certainformulations, such as those used on packaging; in this context“substantially free” means these monomers are not intentionally used inthe polymerization of the acrylic and are therefore present, if at all,in an amount of 1 wt % or less, based on total wt % of the monomers. Inaddition, when using an acrylic resin in the present compositions, the(meth)acrylic resin may be substantially free of unreacted unsaturation.That is, reaction of the (meth)acrylic monomers in the formation of the(meth)acrylic resin will consume the unsaturation. Thus, the(meth)acrylic resins used according to the present invention are notradiation curable, and any residual unsaturation that might remain inthe (meth)acrylic resin upon reaction of the monomers is not enough torender the (meth)acrylic resin radiation curable.

A “silane modified compound” refers to a compound that is the reactionproduct of a silane that has functionality in addition to the silanehydrogen and a compound that will react with this functionality,sometimes referred to herein as the “modifying compound”. A particularlysuitable silane is an aminosilane, in which the alkoxy, such as ethoxyand/or methoxy, functionality reacts with functionality on the modifyingcompound. Any aminosilane can be used, such as those commerciallyavailable from ShinEtsu as KBE-903, KBM-903, KBM-603 and KBM-602.Another suitable silane is epoxy silane, in which the epoxy group reactswith the modifying compound. Epoxy silanes are commercially availablefrom ShinEtsu as KBM-403 and KBM-303. Vinyl silanes and acryloxy silanescan also be used, and are available from ShinEtsu as KBM-1003 andKBE-1003, and KBM-5103 and KBM-503, respectively. Mixtures of silanemodified compounds can be used; a mixture of aminosilane and epoxysilane may be suitable. When the silane comprises aminosilane, thesilane modified compound may be referred to herein as an aminosilanemodified compound, and when the silane comprises epoxy silane as anepoxy silane modified compound.

Any suitable modifying compound(s) can be used, and can be selectedbased on the silane(s) being used and/or the performance characteristicsthat may be achieved from using particular modifying agents. Themodifying compound that will react with the functionality of the silanemay be, for example, a silanol containing compound such as a siliconecomprising at least one silanol group. A “silicone” will be understoodas generally referring to a compound having Si—O bonds. A “siliconecomprising at least one silanol group” refers to a silicone having oneor more Si—OH bonds. Silicones comprising at least one silanol group arecommercially available from SilTech. The weight average molecular weight(“Mw”) of the silicone comprising at least one silanol group can be10,000 or greater, such as 15,000 or greater or 20,000 or greater or40,000 or lower, 35,000 or lower or 30,000 or lower. Any Mw range withinthese endpoints can be used; a particularly suitable Mw range is 17,000to 23,000. Mw as reported herein is measured by GPC using a polystyrenestandard. Particularly suitable silicones are silanol functionalsilsesquioxanes commercially available from Dow Chemical in their RSNline. RSN 217, for example, is a fully phenylated silanol functionalsilsesquioxane and with a degree of substitution of 1.0. RSN 233, forexample, is a silanol functional silsesquioxane with a phenyl to methylratio of 1.3:1 and a degree of substitution of 1.15. RSN 255, forexample, is also a silanol functional silsesquioxane with a phenyl tomethyl ratio of 0.84:1 and a degree of substitution of 1.05. All ofthese values are as reported by the manufacturer, Dow. Other suitablesilanols include linear or branched silanol terminated polysiloxaneresins comprising terminal silanol groups, pendant silanol groups orthose resins comprising both dimethyl and diphenyl groups that alsocontain silanol functionality.

The modifying compound that will react with the functionality of thesilane may be, for example, a hydroxyl containing compound. Aparticularly suitable hydroxyl containing compound is a phenolicnovolak. A phenolic novolak will be understood as referring to an acidcatalyzed phenolic made with an excess of phenolic monomer toformaldehyde. Suitable phenolic novolak products are commerciallyavailable from Durez, as 29008, and Allnex, as PN650. Use of a phenolicnovolak in the silane modified compound allows for the advantages ofusing a phenolic in a coating composition, which is of particularinterest for metal cans because phenolic polymers contribute tocorrosion resistance in a wide variety of foods. In addition, becausephenolic novolak is made with an excess of phenolic monomers versusformaldehyde all of the formaldehyde is consumed during thepolymerization of the novolak. Therefore, novolak phenolics do notgenerate formaldehyde as a byproduct during cure. The present coatingcompositions can therefore be formulated so as to be substantially free,essentially free or completely free of formaldehyde.

The silane modified compound can be prepared prior to adding thecompound to the present coating composition, or can be prepared in-situduring the coating composition preparation. That is, the silane can beadded during formulation of the coating and will react with themodifying compound in-situ. The silane modified compound can also bemade separately. The phenolic novolak and/or silicone comprising atleast one silanol group, for example, can be heated in a flask to whichis added the silane. The amount of silane to modifying compound thatwill react with the silane can vary, such as 15 wt % or greater, 20 wt %or greater or 25 wt % or greater, and 40 wt % or less, such as 30 wt %or less, or 20 to 25 wt % silane, and 85 wt % or less, 80 wt % or lessor 75 wt % or less and 60 wt % or greater such as 70 wt % or greater or75 to 80 wt % modifying compound, with wt % based on total solid weight.

The acid functional acrylic resin and silane modified compound can beblended together to form the coating compositions of present inventionby any means known in the art. For example, the components may beblended together using agitation or using a Cowles blade. The amount ofacid functional acrylic resin in the present coating compositions may be15 wt % or greater, such as 20 wt % or greater or 30 wt % or greater, or35 wt % or lower, such as 30 wt % or lower or 25 wt % or lower; asuitable amount may range, for example, from 15 to 35 wt %. The amountof silane modified compound in the present coating compositions may be45 wt % or greater, such as 50 wt % or greater or 55 wt % or greater, or65 wt % or lower, such as 60 wt % or lower or 55 wt % or lower, where wt% is based on total solids weight of the composition. A wt % of 45 to 65may be particularly suitable.

The coating compositions of the present invention may contain one ormore of several additional compounds. A particularly suitable compound,particularly when the silane comprises aminosilane, is epoxidatedvegetable oil (“EVO”). Any suitable EVO can be used, and can either beobtained commercially or prepared by epoxidizing a vegetable oil.Vegetable oils include but are not limited to corn, cottonseed, linseed,rapeseed, tall, palm, peanut, sesame, sunflower, and soy. Epoxidized soybean oil (“ESBO”) is particularly suitable and is commercially availablefrom a number of sources, such as Hallstar, as PLASTHALL ESO, andArkema, in its VIKOFLEX line, such as VIKOFLEX 7170. ESBO and otherepoxidized vegetable oils are known as plasticizers in materials usingvinyl chlorides. It was surprisingly discovered that a coatingcomposition comprising EVO with an acid functional acrylic resin and anaminosilane modified compound imparts greater corrosion resistance to ametal substrate when such composition is cured as compared to a curedcomposition lacking the EVO. It will be appreciated that the epoxy inthe EVO may react with amine functionality on the aminosilane modifiedcompound. If used, the EVO can be added separately upon formulation ofthe coating composition or can be reacted with the silane modifiedcompound before that compound is added to the composition. The amount ofEVO in the present compositions, if used, can vary, such as 5 wt % orgreater, 7.5 wt % or greater, 10 wt % or greater or 12 wt % or greater,and such as 20 wt % or lower or 15 wt % or lower, with wt % based on thetotal solids weight of the composition. A wt % of 10-12 may beparticularly suitable.

Other epoxidized compounds may be used according to the presentinvention, such as epoxidized polybutadiene.

Another suitable component that can be used in the present compositionsis an amine terminated polyamide. Any amine terminated polyamide can beused according to the present invention. The polyamide, for example, canbe based on a dimer acid. Suitable amine values for the polyamide canvary based on the needs of the user and can range, for example from 220to 250, such as 232 to 242, as determined by titration with HBr inHBr/Acetic acid using methyl violet indicator. The viscosity of thepolyamide can also vary, and can range, for example, from 400 to 800poise, such as 550 to 700 poise, when measured with a #3 spindle at 20RPM by Brookfield viscometer at 40° C. Polyamides are widelycommercially available, such as from Hexion in their EPIKURE line. Theamount of amine terminated polyamide in the present compositions, ifused, can vary, such as 2 wt % or greater, 3.5 wt % or greater, or 5 wt% or greater, and such as 15 wt % or lower, 12.5 wt % or lower, or 10 wt% or lower, with wt % based on the total solids weight of thecomposition. A wt % of 3 to 12 may be particularly suitable.

Another suitable component that can be used in the present compositionsis shellac. Shellac is secreted by the female lac bug, and is thereforea renewable resource. Shellac is commercially available from Renshel inIndia, such as in solid form as RENSHEL 101. The shellac may be presentin the composition in any desired amount, such as 5 wt % or greater, 10wt % or greater, 15 wt % or greater, 20 wt % or greater or 25 wt % orgreater, and such as 35 wt % or lower, 30 wt % or lower, 25 wt % orlower, 20 wt % or lower, or 15 wt % or lower, with wt % based on totalsolids of the coating composition. A wt % of 10 to 20 may beparticularly suitable. Any of the ranges within these parameters can beused.

Coating compositions of the present invention may also contain siliconein addition to any silicone that may be used in the formation of thesilane modified compound. Any suitable silicone can be used, includingthose described above. Other suitable silicones include amino-modifiedsilicone resins containing methyl or phenyl or a combination of methyland phenyl; alkoxy modified silicone resins containing methyl or phenylor a combination of methyl and phenyl; epoxy modified silicone resinscontaining methyl or phenyl or a combination of methyl and phenyl. Ifused, such silicones may be present in an amount of 1 wt % or greater,such as 3 wt % or greater or 5 wt % or greater, or 20 wt % or lower,such as 10 wt % or lower or 7 wt % or lower with wt % based on totalsolids of the coating composition; a wt % of 1 to 3 wt % may beparticularly suitable.

The coating compositions of the present invention may comprise one ormore solvents including water or organic solvents. Suitable organicsolvents include glycols, glycol ether alcohols, alcohols, ketones, andaromatics, such as xylene and toluene, acetates, mineral spirits,naphthas and/or mixtures thereof. “Acetates” include the glycol etheracetates. The solvent can be a non-aqueous solvent. “Non-aqueoussolvent” and like terms means that less than 50% of the solvent iswater. For example, less than 10%, or even less than 5% or 2%, of thesolvent can be water. It will be understood that mixtures of solvents,including or excluding water in an amount of less than 50%, canconstitute a “non-aqueous solvent”. The composition may be aqueous orwater-based. This means that 50% or more of the solvent is water. Theseembodiments have less than 50%, such as less than 20%, less than 10%,less than 5% or less than 2% solvent.

The coating composition may be in solid particulate form, i.e. a powdercoating. Such coatings will be appreciated as being environmentallyfriendly, as only water is released on cure.

If desired, the compositions can comprise other optional materials wellknown in the art of formulating, such as colorants, plasticizers,abrasion resistant particles, anti-oxidants, hindered amine lightstabilizers, UV light absorbers and stabilizers, surfactants, flowcontrol agents, thixotropic agents, fillers, organic cosolvents,reactive diluents, catalysts, grind vehicles, slip agents, moisturescavenger and other customary auxiliaries.

As used herein, the term “colorant” means any substance that impartscolor and/or other opacity and/or other visual effect, e.g. gloss, tothe composition. The colorant can be added to the coating in anysuitable form, such as discrete particles, dispersions, solutions and/orflakes. A single colorant or a mixture of two or more colorants can beused in the coatings of the present invention. Particularly suitable forpackaging coatings are those approved for food contact, such as titaniumdioxide; iron oxides, such as black iron oxide; carbon black;ultramarine blue; phthalocyanines, such as phthalocyanine blue andphthalocyanine green; graphite fibrils; ferried yellow; quindo red; andcombinations thereof, and those listed in Article 178.3297 of the Codeof Federal Regulations, which is incorporated by reference herein.

Example colorants include matting pigments, dyes and tints, such asthose used in the paint industry and/or listed in the Dry ColorManufacturers Association (DCMA), as well as special effectcompositions. A colorant may include, for example, a finely dividedsolid powder that is insoluble but wettable under the conditions of use.A colorant can be organic or inorganic and can be agglomerated ornon-agglomerated. Colorants can be incorporated into the coatings bygrinding or simple mixing. Colorants can be incorporated by grindinginto the coating by use of a grind vehicle, such as an acrylic grindvehicle, the use of which will be familiar to one skilled in the art.

Example pigments and/or pigment compositions include, but are notlimited to, carbazole dioxazine crude pigment, azo, monoazo, disazo,naphthol AS, salt type (lakes), benzimidazolone, condensation, metalcomplex, isoindolinone, isoindoline and polycyclic phthalocyanine,quinacridone, perylene, perinone, diketopyrrolo pyrrole, thioindigo,anthraquinone, indanthrone, anthrapyrimidine, flavanthrone, pyranthrone,anthanthrone, dioxazine, triarylcarbonium, quinophthalone pigments,diketo pyrrolo pyrrole red (“DPPBO red”), titanium dioxide, carbonblack, carbon fiber, graphite, other conductive pigments and/or fillersand mixtures thereof. The terms “pigment” and “colored filler” can beused interchangeably.

Example dyes include, but are not limited to, those that are solventand/or aqueous based such as acid dyes, azoic dyes, basic dyes, directdyes, disperse dyes, reactive dyes, solvent dyes, sulfur dyes, mordantdyes, for example, bismuth vanadate, anthraquinone, perylene aluminum,quinacridone, thiazole, thiazine, azo, indigoid, nitro, nitroso,oxazine, phthalocyanine, quinoline, stilbene, and triphenyl methane.

Example tints include, but are not limited to, pigments dispersed inwater-based or water-miscible carriers such as AQUA-CHEM 896commercially available from Degussa, Inc., CHARISMA COLORANTS andMAXITONER INDUSTRIAL COLORANTS commercially available from AccurateDispersions division of Eastman Chemicals, Inc.

As noted above, the colorant can be in the form of a dispersionincluding, but not limited to, a nanoparticle dispersion. Nanoparticledispersions can include one or more highly dispersed nanoparticlecolorants and/or colorant particles that produce a desired visible colorand/or opacity and/or visual effect. Nanoparticle dispersions caninclude colorants such as pigments or dyes having a particle size ofless than 150 nm, such as less than 70 nm, or less than 30 nm.Nanoparticles can be produced by milling stock organic or inorganicpigments with grinding media having a particle size of less than 0.5 mm.Example nanoparticle dispersions and methods for making them areidentified in U.S. Pat. No. 6,875,800 B2, which is incorporated hereinby reference. Nanoparticle dispersions can also be produced bycrystallization, precipitation, gas phase condensation, and chemicalattrition (i.e., partial dissolution). In order to minimizere-agglomeration of nanoparticles within the coating, a dispersion ofresin-coated nanoparticles can be used. As used herein, a “dispersion ofresin-coated nanoparticles” refers to a continuous phase in which isdispersed discreet “composite microparticles” that comprise ananoparticle and a resin coating on the nanoparticle. Exampledispersions of resin-coated nanoparticles and methods for making themare described, for example, in U.S. Pat. No. 7,605,194 at column 3, line56 to column 16, line 25, the cited portion of which being incorporatedherein by reference.

The photosensitive composition and/or photochromic composition can beassociated with and/or at least partially bound to, such as by covalentbonding, a polymer and/or polymeric materials of a polymerizablecomponent. In contrast to some coatings in which the photosensitivecomposition may migrate out of the coating and crystallize into thesubstrate, the photosensitive composition and/or photochromiccomposition associated with and/or at least partially bound to a polymerand/or polymerizable component in accordance with the present inventionhave minimal migration out of the coating. Example photosensitivecompositions and/or photochromic compositions and methods for makingthem are identified in U.S. Pat. No. 8,153,344, and incorporated hereinby reference.

In general, the colorant can be present in any amount sufficient toimpart the desired visual and/or color effect. The colorant may comprisefrom 1 to 65 weight percent of the present compositions, such as from 3to 40 weight percent or 5 to 35 weight percent, with weight percentbased on the total weight of the compositions.

An “abrasion resistant particle” is one that, when used in a coating,will impart some level of abrasion resistance to the coating as comparedwith the same coating lacking the particles. Suitable abrasion resistantparticles include organic and/or inorganic particles. Examples ofsuitable organic particles include but are not limited to diamondparticles, such as diamond dust particles, and particles formed fromcarbide materials; examples of carbide particles include but are notlimited to titanium carbide, silicon carbide and boron carbide. Examplesof suitable inorganic particles, include but are not limited to silica;alumina; alumina silicate; silica alumina; alkali aluminosilicate;borosilicate glass; nitrides including boron nitride and siliconnitride; oxides including titanium dioxide and zinc oxide; quartz;nepheline syenite; zircon such as in the form of zirconium oxide;buddeluyite; and eudialyte. Particles of any size can be used, as canmixtures of different particles and/or different sized particles. Forexample, the particles can be microparticles, having an average particlesize of 0.1 to 50, 0.1 to 20, 1 to 12, 1 to 10, or 3 to 6 microns, orany combination within any of these ranges. The particles can benanoparticles, having an average particle size of less than 0.1 micron,such as 0.8 to 500, 10 to 100, or 100 to 500 nanometers, or anycombination within these ranges.

Any slip agent can be used according to the present invention such asthose commercially available from BYK Chemie or Dow Corning. A wax canalso be used such as polyolefin wax or paraffin.

The coating compositions of the present invention and/or the componentsthereof may be substantially free, may be essentially free and/or may becompletely free of bisphenol A (“BPA”) and compounds derived frombisphenol A, such as bisphenol A diglycidyl ether (“BADGE”). Suchcompounds are sometimes referred to as “BPA non intent” because BPA,including derivatives or residues thereof, are not intentionally addedbut may be present in trace amounts because of impurities or unavoidablecontamination from the environment. The coating compositions and/orcomponents thereof can also be substantially free and may be essentiallyfree and/or may be completely free of bisphenol F (“BPF”) and compoundsderived from bisphenol F, such as bisphenol F diglycidyl ether(“BFDGE”). The term “substantially free” as used in this context meansthe coating composition contains less than 1000 parts per million (ppm),“essentially free” means less than 100 ppm and “completely free” meansless than 20 parts per billion (ppb) of any of the above mentionedcompounds, derivatives or residues thereof.

In addition, the compositions of the present invention and/or componentsthereof may be substantially free, may be essentially free and/or may becompletely free of formaldehyde and/or phenolic cross-linker, such asphenolic resin. The term “substantially free” as used in this contextmeans the compositions contain, and/or release on cure, less than 1000parts per million (ppm), “essentially free” means less than 100 ppm and“completely free” means less than 100 parts per billion (ppb) offormaldehyde compounds, phenolic cross-linker, derivatives or residuesthereof.

The present compositions can be applied to any substrates known in theart, for example, automotive substrates, marine substrates, industrialsubstrates, packaging substrates, wood flooring and furniture, apparel,electronics including housings and circuit boards and including consumerelectronics such as housings for computers, notebooks, smartphones,tablets, televisions, gaming equipment, computer equipment, computeraccessories, MP3 players, and the like, glass and transparencies, sportsequipment including golf balls, and the like. Accordingly, the presentinvention is further directed to a substrate coated at least in partwith any of the coating compositions described above. These substratescan be, for example, metallic or non-metallic. Metallic substratesinclude tin, steel, tin-plated steel, chromium passivated steel,galvanized steel, aluminum, aluminum foil. Metal sheet as used hereinrefers to flat metal sheet and coiled metal sheet, which is coiled,uncoiled for coating and then re-coiled for shipment to a manufacturer.Non-metallic substrates include polymeric, plastic, polyester,polyolefin, polyamide, cellulosic, polystyrene, polyacrylic,poly(ethylene naphthalate), polypropylene, polyethylene, nylon, EVOH,polylactic acid, other “green” polymeric substrates,poly(ethyleneterephthalate) (“PET”), polycarbonate, polycarbonateacrylobutadiene styrene (“PC/ABS”), polyamide, wood, veneer, woodcomposite, particle board, medium density fiberboard, cement, stone,glass, paper, cardboard, textiles, leather both synthetic and natural,and the like. The substrate can be one that has been already treated insome manner, such as to impart visual and/or color effect. Suitablesubstrates can include those in which powder coatings are typicallyapplied.

The compositions of the present invention can be applied by any meansstandard in the art, such as electrocoating, spraying, electrostaticspraying, dipping, rolling, brushing, and the like.

The compositions can be applied to a dry film thickness of 0.04 mils to4 mils, such as 0.3 to 2 or 0.7 to 1.3 mils. The compositions can alsobe applied to a dry film thickness of 0.1 mils or greater, 0.5 mils orgreater 1.0 mils or greater, 2.0 mils or greater, 5.0 mils or greater,or even thicker. In some applications, a dry film thickness of 1-20microns, such as 2-6 microns, is desired.

The compositions of the present invention can be used alone, or incombination with one or more other compositions, such as a coatingsystem having two or more layers. For example, the compositions of thepresent invention can comprise a colorant or not and can be used as aprimer, basecoat, and/or top coat. For substrates coated with multiplecoatings, one or more of those coatings can be coatings as describedherein. The present coatings can also be used as a packaging “size”coating, wash coat, spray coat, end coat, and the like.

It will be appreciated that the compositions described herein can beeither one component (“1K”), or multi-component compositions such as twocomponent (“2K”) or more. A 1K composition will be understood asreferring to a composition wherein all the coating components aremaintained in the same container after manufacture, during storage, etc.A 1K composition can be applied to a substrate and cured by anyconventional means, such as by heating, forced air, and the like. Thepresent compositions can also be multi-component, which will beunderstood as compositions in which various components are maintainedseparately until just prior to application. The present compositions canbe thermoplastic or thermosetting.

The composition can be a clearcoat. A clearcoat will be understood as acoating that is substantially transparent or translucent. A clearcoatcan therefore have some degree of color, provided it does not make theclearcoat opaque or otherwise affect, to any significant degree, theability to see the underlying substrate. The clearcoats of the presentinvention can be used, for example, in conjunction with a pigmentedbasecoat. The clearcoat can be formulated as is known in the coatingsart.

The composition may also comprise a colorant, such as a pigmentedbasecoat used in conjunction with a clearcoat, or as a pigmentedmonocoat. Such coating layers are used in various industries to impart adecorative and/or protective finish. For example, such a coating orcoating system may be applied to a vehicle. “Vehicle” is used herein inits broadest sense and includes all types of vehicles, such as but notlimited to cars, trucks, buses, vans, golf carts, motorcycles, bicycles,railroad cars, airplanes, helicopters, boats of any size and the like.It will be appreciated that the portion of the vehicle that is coatedaccording to the present invention may vary depending on why the coatingis being used. For example, anti-chip primers may be applied to some ofthe portions of the vehicle as described above. When used as a coloredbasecoat or monocoat, the present coatings will typically be applied tothose portions of the vehicle that are visible such as the roof, hood,doors trunk lid and the like, but may also be applied to other areassuch as inside the trunk, inside the door and the like especially whenthe compositions are formulated as sealants or adhesives; they can alsobe applied to those portions of the car that are in contact with thedriver and/or passengers, such as the steering wheel, dashboard, gearshift, controls, door handle and the like. Clearcoats will typically beapplied to the exterior of a vehicle.

The compositions of the present invention are also suitable for use aspackaging coatings. The application of various pretreatments andcoatings to packaging is well established. Such treatments and/orcoatings, for example, can be used in the case of metal cans, whereinthe treatment and/or coating may be used to retard or inhibit corrosion,provide a decorative coating, and/or provide ease of handling during themanufacturing process. Coatings can be applied to the interior of suchcans to prevent the contents from contacting the metal of the container.Contact between the metal and a food or beverage, for example, can leadto corrosion of a metal container, which can then contaminate the foodor beverage. This is particularly true when the contents of the can areacidic in nature. The coatings applied to the interior of metal cansalso help prevent corrosion in the headspace of the cans, which is thearea between the fill line of the product and the can lid; corrosion inthe headspace is particularly problematic with food products having ahigh salt content. Coatings can also be applied to the exterior of metalcans. Certain coatings of the present invention are particularlyapplicable for use with coiled metal stock, such as the coiled metalstock from which the ends of cans are made (“can end stock”), and endcaps and closures are made (“cap/closure stock”). Since coatingsdesigned for use on can end stock and cap/closure stock are typicallyapplied prior to the piece being cut and stamped out of the coiled metalstock, they are typically flexible and extensible. For example, suchstock is typically coated on both sides. Thereafter, the coated metalstock is punched. For can ends, the metal is then scored for the“pop-top” opening and the pop-top ring is then attached with a pin thatis separately fabricated. The end is then attached to the can body by anedge rolling process. A similar procedure is done for “easy open” canends. For easy open can ends, a score substantially around the perimeterof the lid allows for easy opening or removing of the lid from the can,typically by means of a pull tab. For caps and closures, the cap/closurestock is typically coated, such as by roll coating, and the cap orclosure stamped out of the stock; it is possible, however, to coat thecap/closure after formation. Coatings for cans subjected to relativelystringent temperature and/or pressure requirements should also beresistant to popping, corrosion, blushing and/or blistering.

Accordingly, the present invention is further directed to a packagecoated at least in part with any of the coating compositions describedabove. A “package” is anything used to contain another item,particularly for shipping from a point of manufacture to a consumer, andfor subsequent storage by a consumer. A package will be thereforeunderstood as something that is sealed so as to keep its contents freefrom deterioration until opened by a consumer. The manufacturer willoften identify the length of time during which the food or beverage willbe free from spoilage, which typically ranges from several months toyears. Thus, the present “package” is distinguished from a storagecontainer or bakeware in which a consumer might make and/or store food;such a container would only maintain the freshness or integrity of thefood item for a relatively short period. “Package” as used herein meansthe complete package itself or any component thereof, such as an end,lid, cap and the like. For example, a “package” coated with any of thecoating compositions described herein might include a metal can in whichonly the can end or a portion thereof is coated. A package according tothe present invention can be made of metal or non-metal, for example,plastic or laminate, and be in any form. An example of a suitablepackage is a laminate tube. Another example of a suitable package ismetal can. The term “metal can” includes any type of metal can,container or any type of receptacle or portion thereof that is sealed bythe food/beverage manufacturer to minimize or eliminate spoilage of thecontents until such package is opened by the consumer. One example of ametal can is a food can; the term “food can(s)” is used herein to referto cans, containers or any type of receptacle or portion thereof used tohold any type of food and/or beverage. “Beverage can” may also be usedto refer more specifically to a food can in which a beverage ispackaged. The term “metal can(s)” specifically includes food cans(including beverage cans) and also specifically includes “can ends”including “E-Z open ends”, which are typically stamped from can endstock and used in conjunction with the packaging of food and beverages.The term “metal cans” also specifically includes metal caps and/orclosures such as bottle caps, screw top caps and lids of any size, lugcaps, and the like. The metal cans can be used to hold other items aswell, including, but not limited to, personal care products, bug spray,spray paint, and any other compound suitable for packaging in an aerosolcan. The cans can include “two piece cans” and “three-piece cans” aswell as drawn and ironed one-piece cans; such one piece cans often findapplication with aerosol products. Packages coated according to thepresent invention can also include plastic bottles, plastic tubes,laminates and flexible packaging, such as those made from PE, PP, PETand the like. Such packaging could hold, for example, food, toothpaste,personal care products and the like.

The coating can be applied to the interior and/or the exterior of thepackage. For example, the coating can be rollcoated onto metal used tomake a two-piece food can, a three-piece food can, can end stock and/orcap/closure stock. The coating is applied to a coil or sheet by rollcoating; the coating is then cured by radiation and can ends are stampedout and fabricated into the finished product, i.e. can ends. The coatingcould also be applied as a rim coat to the bottom of the can; suchapplication can be by roll coating. The rim coat functions to reducefriction for improved handling during the continued fabrication and/orprocessing of the can. The coating can be applied to the “side stripe”of a metal can, which will be understood as the seam formed duringfabrication of a three-piece can. The coating can also be applied tocaps and/or closures; such application can include, for example, aprotective varnish that is applied before and/or after formation of thecap/closure and/or a pigmented enamel post applied to the cap,particularly those having a scored seam at the bottom of the cap.Decorated can stock can also be partially coated externally with thecoating described herein, and the decorated, coated can stock used toform various metal cans.

Metal coils, having wide application in many industries, are alsosubstrates that can be coated according to the present invention. Coilcoatings also typically comprise a colorant.

After application to the substrate, the coating composition may be curedby any appropriate means. In some applications a cure of 425° F. orlower, such as 415 or lower or 400 or lower for 5 minutes or less, suchas 4.5 minutes or less may be desired and can be achieved according tothe present invention. In other applications, a longer cure time mightbe appropriate, such as a cure time of ten to twelve minutes at 380° F.to 425° F. Suitable cure conditions can be determined based on the needsof the user. Accordingly, the present coatings can be used across abroad range of industries and cure conditions.

As used herein, unless otherwise expressly specified, all numbers suchas those expressing values, ranges, amounts or percentages may be readas if prefaced by the word “about”, even if the term does not expresslyappear. Also, any numerical range recited herein is intended to includeall sub-ranges subsumed therein. Singular encompasses plural and viceversa. For example, although reference is made herein to “an” acidfunctional acrylic resin, “a” silane modified compound, “a” modifyingcompound, “a” phenolic novolak, “a” silicone comprising at least onesilanol group, and the like, one or more of each of these and any othercomponents can be used. As used herein, the term “polymer” refers tooligomers and both homopolymers and copolymers, and the prefix “poly”refers to two or more. (Meth)acrylic, and like terms, refers to bothacrylic and methacrylic. Including, for example, and like terms meansincluding, for example, but not limited to. When ranges are given, anyendpoints of those ranges and/or numbers within those ranges can becombined within the scope of the present invention. When maximum andminimum amounts are given, any such amounts can be combined to specifyranges of ingredients; any numbers within those ranges can be combinedwithin the scope of the present invention. The word “comprising” andforms of the word “comprising”, as used in this description and in theclaims, does not limit the present invention to exclude any variants oradditions. Additionally, although the present invention has beendescribed in terms of “comprising”, the processes, materials, andcoating compositions detailed herein may also be described as“consisting essentially of” or “consisting of”.

Non-limiting aspects of the invention include:

1. A coating composition comprising an acid functional acrylic resin andan aminosilane modified compound.

2. The coating composition of aspect 1, wherein the functionality on thesilane modified compound and the carboxylic acid functionality on theacrylic resin react to form a crosslinked coating.

3. The coating composition of any preceding aspect, wherein the silanein the silane modified compound comprises aminosilane, epoxy silane orboth.

4. The coating composition of any preceding aspect, wherein the silanemodified compound comprises the reaction product of a silane and aphenolic novolak.

5. The coating composition of aspect 4, wherein the phenolic novolakcomprises a t-butyl novolak or a cresol novolak.

6. The coating composition of any preceding aspect, wherein the silanemodified compound comprises the reaction product of a silane and asilicone comprising at least one silanol group.

7. The coating composition of aspect 6, wherein the silicone comprises asilanol functional silsesquioxane.

8. The coating composition of any preceding aspect, wherein the silanecomprises aminosilane.

9. The coating composition of any preceding aspect, wherein thecomposition further comprises EVO, such as ESBO, polybutadiene,polyamine terminated polyamide, silicone and/or shellac.

10. The coating composition of any preceding aspect, wherein thecomposition comprises an aminosilane modified compound that comprisesthe reaction product of an aminosilane and a phenolic novolak and anaminosilane modified compound that comprises the reaction product of anaminosilane and a silicone comprising at least one silanol group.11. The coating composition of any preceding aspect, wherein thecomposition comprises an aminosilane modified compound that comprisesthe reaction product of an aminosilane and a first phenolic novolak andan aminosilane modified compound that comprises the reaction product ofan aminosilane and a second phenolic novolak.12. The coating composition of any preceding aspect, wherein thecomposition and/or components thereof are substantially free,essentially free, or completely free of BPA, BPF and derivativesthereof.13. The coating composition of any preceding aspect, wherein thecomposition and/or components thereof are substantially free,essentially free, or completely free of formaldehyde and/or phenoliccross-linker.14. The coating composition of any preceding aspect, wherein thecomposition and/or components thereof are substantially free,essentially free, or completely free of styrene, ethyl acrylate and/oracrylamide, such as N-BMA.15. A substrate coated at least in part with the coating composition anypreceding aspect.16. The substrate of aspect 15, wherein the substrate comprises apackage.17. The package of aspect 16, wherein the package is a metal can.18. The package of aspect 17, wherein the metal can is a food can orbeverage can.19. The package of aspect 17, wherein the metal can is a food can or abeverage can coated at least in part on the inside with the coatingcomposition of any aspects 1-14.

EXAMPLES

The following examples are intended to illustrate the invention andshould not be construed as limiting the invention in any way.

Example 1

Acrylic A Solids Ethyl methacrylate 33% Methyl acrylate 36% Methacrylicacid 31% 100% 

Acrylic A composition in solvent Ethyl methacrylate 671 Methyl Acrylate729 Methacrylic acid 630 Butanol 2376 T butyl peroctoate 99

Acrylic A was prepared in a 5 liter round bottom flask by chargingbutanol, heating to reflux, and adding the monomers over three hoursusing T butyl peroctoate as a free radical initiator.

Coating Composition 1 Resin solids 29-008P at 60 wt % solids inpentanol¹ 70% KBM-603²  5% Acrylic A at 23.5 wt % solids in water at 30%25% neutralization 100%  ¹t-butyl novolak from Durez ²aminosilane fromShinEtsu

Coating composition 1, final coating 29-008P solution at 60% solids 1296grams KBM-603 56 grams Acrylic A at 23.5 wt % solids in water 1182 gramsOleic Acid 10 grams SURFYNOL 104³ 15 grams DI water 1166 grams ³wettingaid from Air Products

Coating composition 1 was made by charging the 29-088P solution into astainless steel tank and then adding the aminosilane under agitationwith a paddle blade at 700 RPM. The components were allowed to mix forfive minutes, after which Acrylic A solution was added. The componentswere mixed for 15 minutes after which the oleic acid and the SURFYNOLwere added. DI water was used to adjust the viscosity to 21 seconds asmeasured by a #4 Ford cup and to a solids of about 27 wt %.

Example 2

Aminosilane modified phenolic novolaks were prepared by charging 29-008Psolution in pentanol to a three liter flask equipped with a Dean Starktrap and condenser. The novolak solution was heated to 200° F. and theaminosilane was added; methanol was evolved. The mixture was heated at240° F. until the methanol was removed. The same procedure was used tomake the Novolak B graft.

Novolak A graft 29-008P at 60 wt % solids in pentanol 1500 grams KBM-603240 grams 1740 grams

Novolak B graft PN650 at 55 wt % solids in pentanol⁴ 1500 grams KBM-603210 grams 1710 grams ⁴cresole novolak from Allnex

Coating composition 2 was prepared by neutralizing Acrylic A to 30% withdimethylethanolamine, and reducing with DI water to 30 wt % solids.Novolak A was added to the Acrylic A solution with agitation with aCowles blade at 700 RPM. Then 25% of the DI water was added to reducethe viscosity and the product allowed to mix for 15 minutes. Novolak Bwas added under agitation at 700 RPM and the product allowed to mix for15 minutes. EPIKURE was added and mixed for 15 minutes, then the oleicacid and SURFYNOL were added. The remaining water was added to adjustthe viscosity to 22 seconds as measured using a #4 Ford cup and to asolids of about 27 wt %.

Coating Composition 2 Resin solids Novolak A graft solids 55% Novolak Bgraft solids 20% Acrylic A at 30 wt % solids in water at 30% 20%neutralization EPIKURE 3115⁵ at 80 wt % solids in butanol  5% 100% ⁵amine terminated polyamide from Hexion

Coating composition 2, final coating Novolac A graft solution 839.60Novolac Bgraft solution 330.0 Acrylic A at 30 wt % solids 666.67 EPIKUREat 80 wt % solids in butanol 62.5 Oleic Acid 20 SURFYNOL 104 15 DI water1694 3627.77

Example 3

Acrylic B was prepared as described above for Acrylic A using thefollowing:

Acrylic B Solids Ethyl methacrylate 37% Methyl acrylate 36% Methacrylicacid 27% 100% 

Acrylic B composition in solvent Ethyl methacrylate 752 Methyl Acrylate730 Methacrylic acid 548 Butanol 2376 T butyl peroctoate 99

An aminosilane modified silicone was prepared by charging RSN217solution in pentanol to a three liter flask equipped with a Dean Starktrap and condenser. The silicone solution was heated to 200° F. and theaminosilane was added; methanol was evolved. The mixture was heated at240° F. until the methanol was removed.

Silicone A RSN 217⁶ at 60 wt % solids in pentanol 1500 grams KBM-603 726grams 2226 grams ⁶RSN 217 = Silsesquioxane silicone from Dow Chemical

Coating composition 3 was prepared by neutralizing Acrylic A to 30% withdimethylethanolamine, and reducing with DI water to 30 wt % solids.Silicone A was added to the Acrylic A solution with agitation with aCowles blade at 700 RPM. Then 25% of the DI water was added to reducethe viscosity and the product allowed to mix for 15 minutes. Novolak Bwas added under agitation at 700 RPM and the product allowed to mix for15 minutes. EPIKURE was added and mixed for 15 minutes, then the oleicacid and SURFYNOL were added. The remaining water was added to adjustthe viscosity to 22 seconds as measured using a #4 Ford cup and to asolids of about 27 wt %.

Coating Composition 3 Resin solids Silicone A graft solids 55% Novolak Bgraft solds 20% Acrylic A at 30 wt % solids in water at 30% 20%neutralization EPIKURE 3115 at 80 wt % solids in butanol  5% 100% 

Coating composition 3, final coating Silicone A solution 753.4 Novolac Bsolution 330.0 Acrylic A at 30 wt % solids 666.67 EPIKURE at 80 wt %solids in butanol 62.5 Oleic Acid 20 SURFYNOL 104 15 DI water 16943541.57

Example 4

Novolak C graft 29-008P at 60 wt % solids in pentanol 1000 grams KBM-603138 grams ESBO 456 grams 1594

Coating composition 4 resin solids Novolak C graft solids 55% Novolak Bgraft solids 20% Acrylic A at 30 wt % solids in water at 30% 20%neutralization EPIKURE 3115 at 80 wt % solids in butanol  5% 100% 

Coating composition 4, final coating Novolak C graft solids 734.2Novolak B graft solids 330.6 Acrylic A at 30 wt % solids in water at 30%666.67 neutralization EPIKURE 3115 at 80 wt % solids in butanol 62.5Oleic acid 20 SURFYNOL 15 DI water 1694 3527.47

Novolak graft C was made by charging the 29008P solution in pentanol toa 3-liter flask equipped with a Dean Stark trap. The novolak solutionwas heated to 200° F. then the KBM-603 was added. Methanol was evolved.Heating was continued to 240° F. until all the methanol was removed. TheESBO was added once the novolak solution reached 240° F. and was heldthere for two hours.

Coating Composition 4 was made as generally described above for CoatingComposition 3.

Example 5

Coating Composition 5 was made as generally described above, with theshellac added with a Cowles blade at 600 RPM after the Acrylic wasreduced to 30 wt % solids.

Coating Composition 5 Resin solids Novolak A graft solids 45% Novolak Bgraft solids 25% Acrylic A at 30 wt % solids in water at 30% 20%neutralization Shellac at 50 wt % solids in butanol 10% 100% 

Coating composition 5, final coating Novolak A graft solution 687.00Novolac B graft solution 413.00 Acrylic A at 30% solids 666.67 Shellacat 50% solids in butanol 200 Oleic Acid 20 SURFYNOL 104 15 DI water 16943695.67

Example 6

An epoxy silane modified novolak was prepared by charging 29-008P inpentanol to a three liter flask equipped with a Dean Stark trap andcondenser. The novolak solution was heated to 200° F. and the epoxysilane was added; methanol was evolved. The mixture was heated at 240°F. until the methanol was removed.

Novolak D graft 29-008P at 60 wt % solids in pentanol 1000 gramsKBM-403⁷ 132 grams 1132 grams ⁷epoxy silane from ShinEtsu

Coating Composition 6 was prepared by neutralizing Acrylic A to 30% withdimethylethanolamine, and reduced with DI water to 30 wt % solids.Novolak A was added to Acrylic A solution with agitation with a Cowlesblade at 700 RPM. Then was added 25% of the DI water to reduce theviscosity and the product was allowed to mix for 15 minutes. Novolak Dwas added under agitation at 700 RPM and the product allowed to mix for15 minutes. EPIKURE was added and mixed for 15 minutes, then the oleicacid and SURFYNOL were added. The remaining water was added to adjustthe viscosity to 22 seconds as measured using a #4 Ford cup and to asolids of about 27 wt %.

Coating Composition 6 Resin solids Novolak A graft solids 55% Novolak Dgraft solids 20% Acrylic A at 30 wt % solids in water at 30% 20%neutralization EPIKURE 3115 at 80 wt % solids in butanol  5% 100% 

Coating composition 6, final coating Acrylic A at 30% solids 666.7 gramsNovolak A graft solution 839.7 grams Novolak D graft solution 309.3grams EPIKURE 3115 at 80% solids in butanol 62.5 grams Oleic Acid 20grams SURFYNOL 104 15 grams DI water 1790.5 grams 3703.7 grams

Example 7

Coating compositions 1-6 were airless spray applied to a 300×407 can at300 mgs and baked for five minutes in an inside bake oven at a peakmetal temperature of 425° F. on the upper side wall. All of the coatingswere found to have over 100 MEK double rubs as measured by placing acotton cloth over the rounded end of a Ball PEEN Hammer then soaking itwith methyl ethyl ketone and rubbing the baked panel with the weight ofthe hammer and the M.E.K. soaked cloth. All of the coatings passed steamprocess for one hour at 250° F. with no blush or adhesion loss uponcrosshatch and taping. Steam process is a test where the baked cans wereplaced inside of a steam retort and steam was heated to 250° F. to testthe film for blush, a whitening of the film, or adhesion loss afterscratching through the film with a razor blade in a crosshatch pattern.

What is claimed is:
 1. A coating composition comprising an acidfunctional acrylic resin and a silane modified compound, wherein thesilane modified compound comprises the reaction product of anaminosilane and a phenolic novolak.
 2. The coating composition of claim1, wherein the silane modified compound further comprises epoxy silane.3. The coating composition of claim 1, wherein the silane modifiedcompound further comprises the reaction product of an aminosilane and asilicone comprising at least one silanol group.
 4. The coatingcomposition of claim 1, wherein the silane modified compound comprisesthe reaction product of an aminosilane and a first phenolic novolak andreaction product of an aminosilane and a second phenolic novolak.
 5. Thecoating composition of claim 1, further comprising epoxidized vegetableoil.
 6. The coating composition of claim 5, wherein the epoxidizedvegetable oil comprises epoxidized soy bean oil.
 7. The coatingcomposition of claim 1, further comprising shellac.
 8. The coatingcomposition of claim 1, further comprising amine terminated polyamide.9. The coating composition of claim 1, wherein the acid functionalacrylic resin comprises methacrylic acid, methyl acrylate and ethylmethacrylate.
 10. The coating composition of claim 1, wherein thephenolic novolak comprises a t-butyl novolak and/or a cresol novolak.11. The coating composition of claim 3, wherein the silicone comprisingat least one silanol group comprises a silanol functionalsilsesquioxane.
 12. A substrate coated at least in part with the coatingcomposition of claim
 1. 13. The substrate of claim 12, wherein thesubstrate is a package.
 14. The substrate of claim 13, wherein thepackage is a metal can.